cast pid_t's to uintmax_t to improve portability

Some systems (like e.g. OpenSolaris) define pid_t as long,
therefore all our sprintf that use %i/%d cause a compiler warning
beacuse of the implicit long->int cast. To make sure that
we fit the limits, we display pids as PRIuMAX and cast them explicitly
to uintmax_t.

Signed-off-by: David Soria Parra <dsp@php.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-commit.c

@@ -320,7 +320,7 @@ static char *prepare_index(int argc, const char **argv, const char *prefix)
 		die("unable to write new_index file");
 
 	fd = hold_lock_file_for_update(&false_lock,
-				       git_path("next-index-%d", getpid()), 1);
+				       git_path("next-index-%"PRIuMAX, (uintmax_t) getpid()), 1);
 
 	create_base_index();
 	add_remove_files(&partial);