lib/, src/: Say 'long' instead of 'long int'

We were using 'long' in most places, so be consistent and use it
everywhere.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

src/useradd.c

@@ -875,7 +875,7 @@ static struct group * get_local_group(char * grp_name)
 {
 	const struct group *grp;
 	struct group *result_grp = NULL;
-	long long int gid;
+	long long  gid;
 	char *endptr;
 
 	gid = strtoll (grp_name, &endptr, 10);