perf expr: Remove jevents case workaround

jevents.py no longer lowercases metrics and altering the case can cause
hashmap lookups to fail, so remove.

Signed-off-by: Ian Rogers <[e-mail]>
Cc: Ahmad Yasin <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Andi Kleen <[e-mail]>
Cc: Caleb Biggers <[e-mail]>
Cc: Florian Fischer <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: John Garry <[e-mail]>
Cc: Kajol Jain <[e-mail]>
Cc: Kan Liang <[e-mail]>
Cc: Kshipra Bopardikar <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Miaoqian Lin <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Perry Taylor <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Samantha Alt <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Cc: Thomas Richter <[e-mail]>
Cc: Xing Zhengjun <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/expr.c

···
 {
 	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
 	char *old_key = NULL;
-	char *name, *p;
+	char *name;
 	int ret;
 
 	data_ptr = zalloc(sizeof(*data_ptr));
···
 		free(data_ptr);
 		return -ENOMEM;
 	}
-
-	/*
-	 * The jevents tool converts all metric expressions
-	 * to lowercase, including metric references, hence
-	 * we need to add lowercase name for metric, so it's
-	 * properly found.
-	 */
-	for (p = name; *p; p++)
-		*p = tolower(*p);
 
 	/*
 	 * Intentionally passing just const char pointers,