selftests/bpf: Fix btf_dump test under new clang

New clang version changed ([0]) type name in dwarf from "long int" to "long",
this is causing btf_dump tests to fail.

[0] https://github.com/llvm/llvm-project/commit/f6a561c4d6754b13165a49990e8365d819f64c86

Signed-off-by: Yucong Sun <[e-mail]>
Signed-off-by: Andrii Nakryiko <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

tools/testing/selftests/bpf/progs/btf_dump_test_case_bitfields.c

···
 /*
  *struct bitfields_only_mixed_types {
  *	int a: 3;
- *	long int b: 2;
+ *	long b: 2;
  *	_Bool c: 1;
  *	enum {
  *		A = 0,
···
 
 struct bitfields_only_mixed_types {
 	int a: 3;
-	long int b: 2;
+	long b: 2;
 	bool c: 1; /* it's really a _Bool type */
 	enum {
 		A, /* A = 0, dumper is very explicit */
···
  *	char: 4;
  *	int a: 4;
  *	short b;
- *	long int c;
- *	long int d: 8;
+ *	long c;
+ *	long d: 8;
  *	int e;
  *	int f;
  *};
···
  *struct bitfield_flushed {
  *	int a: 4;
  *	long: 60;
- *	long int b: 16;
+ *	long b: 16;
  *};
  *
  */

tools/testing/selftests/bpf/progs/btf_dump_test_case_packing.c

···
 struct nested_packed {
 	char: 4;
 	int a: 4;
-	long int b;
+	long b;
 	struct {
 		char c;
 		int d;
···
 
 union union_does_not_need_packing {
 	struct {
-		long int a;
+		long a;
 		int b;
 	} __attribute__((packed));
 	int c;

tools/testing/selftests/bpf/progs/btf_dump_test_case_padding.c

···
 /* ----- START-EXPECTED-OUTPUT ----- */
 struct padded_implicitly {
 	int a;
-	long int b;
+	long b;
 	char c;
 };
 

tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c

···
 			const char *d;
 		} e;
 		union {
-			volatile long int f;
+			volatile long f;
 			void * restrict g;
 		};
 	};