perf tools: Replace STR() calls with __stringify()

Both do the same thing, the later is the one we get from
linux/stringify.h, i.e. we now use the same function name/practice as
the kernel sources.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-w2sxa5o4bfx7fjrd5mu4zmke@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/arch/arm/util/dwarf-regs.c

@@ -9,6 +9,7 @@
  */
 
 #include <stddef.h>
+#include <linux/stringify.h>
 #include <dwarf-regs.h>
 
 struct pt_regs_dwarfnum {
@@ -16,10 +17,9 @@ struct pt_regs_dwarfnum {
 	unsigned int dwarfnum;
 };
 
-#define STR(s) #s
 #define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
 #define GPR_DWARFNUM_NAME(num) \
-	{.name = STR(%r##num), .dwarfnum = num}
+	{.name = __stringify(%r##num), .dwarfnum = num}
 #define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
 
 /*