perf dso: Minor refactor to allow clang's Wthread-safety analysis

The pattern:

```
if (x) {
lock(...)
}
block1;
if (x) {
unlock(...)
}
```

defeats clang's -Wthread-safety analysis where it complains of locks
held on one path and not another.

Add helper functions for "block1" then restructure as:

```
if (x) {
lock(...);
block1();
unlock(...);
} else {
block1();
}
```

Signed-off-by: Ian Rogers <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Athira Rajeev <[e-mail]>
Cc: Bill Wendling <[e-mail]>
Cc: Chaitanya S Prakash <[e-mail]>
Cc: Fei Lang <[e-mail]>
Cc: Howard Chu <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Justin Stitt <[e-mail]>
Cc: Kan Liang <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Nathan Chancellor <[e-mail]>
Cc: Nick Desaulniers <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Stephen Brennan <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/dso.c

···
 	return dso;
 }
 
+static void __dso__set_long_name_id(struct dso *dso, const char *name, bool name_allocated)
+{
+	if (dso__long_name_allocated(dso))
+		free((char *)dso__long_name(dso));
+
+	RC_CHK_ACCESS(dso)->long_name = name;
+	RC_CHK_ACCESS(dso)->long_name_len = strlen(name);
+	dso__set_long_name_allocated(dso, name_allocated);
+}
+
 static void dso__set_long_name_id(struct dso *dso, const char *name, bool name_allocated)
 {
 	struct dsos *dsos = dso__dsos(dso);
···
 		 * renaming the dso.
 		 */
 		down_write(&dsos->lock);
-	}
-
-	if (dso__long_name_allocated(dso))
-		free((char *)dso__long_name(dso));
-
-	RC_CHK_ACCESS(dso)->long_name = name;
-	RC_CHK_ACCESS(dso)->long_name_len = strlen(name);
-	dso__set_long_name_allocated(dso, name_allocated);
-
-	if (dsos) {
+		__dso__set_long_name_id(dso, name, name_allocated);
 		dsos->sorted = false;
 		up_write(&dsos->lock);
+	} else {
+		__dso__set_long_name_id(dso, name, name_allocated);
 	}
 }
 
···
 	dso__set_long_name_id(dso, name, name_allocated);
 }
 
+static void __dso__set_short_name(struct dso *dso, const char *name, bool name_allocated)
+{
+	if (dso__short_name_allocated(dso))
+		free((char *)dso__short_name(dso));
+
+	RC_CHK_ACCESS(dso)->short_name		  = name;
+	RC_CHK_ACCESS(dso)->short_name_len	  = strlen(name);
+	dso__set_short_name_allocated(dso, name_allocated);
+}
+
 void dso__set_short_name(struct dso *dso, const char *name, bool name_allocated)
 {
 	struct dsos *dsos = dso__dsos(dso);
···
 		 * renaming the dso.
 		 */
 		down_write(&dsos->lock);
-	}
-	if (dso__short_name_allocated(dso))
-		free((char *)dso__short_name(dso));
-
-	RC_CHK_ACCESS(dso)->short_name		  = name;
-	RC_CHK_ACCESS(dso)->short_name_len	  = strlen(name);
-	dso__set_short_name_allocated(dso, name_allocated);
-
-	if (dsos) {
+		__dso__set_short_name(dso, name, name_allocated);
 		dsos->sorted = false;
 		up_write(&dsos->lock);
+	} else {
+		__dso__set_short_name(dso, name, name_allocated);
 	}
 }