perf ui hists: Include limits.h for PATH_MAX definition

Looking at switch_data_file(), it uses the POSIX constant PATH_MAX.
Omitting the explicit inclusion of limits.h can cause build failures on
musl libc systems, which do not implicitly include headers in the same way
glibc does. Fix this by explicitly including <limits.h> at the top of
tools/perf/ui/browsers/hists.c.

Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

tools/perf/ui/browsers/hists.c

@@ -2,6 +2,7 @@
 #include <dirent.h>
 #include <errno.h>
 #include <inttypes.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>