libmakepkg: ensure emptydir find command acts on individual directories

Using "-exec command {} +" systax exits on any error.  Such errors occur when
running rmdir on a non-empty directory.  Switch to "{} ;" syntax instead which
avoids exiting before the find command is completed.

Fixes FS#48515.

Note, we can not use "-empty" in the find command because it is not supported
by Busybox find, and the "--ignore-fail-on-non-empty" flag for rmdir is not
available on BSD rmdir variants.

Signed-off-by: Allan McRae <allan@archlinux.org>
(cherry picked from commit baf1ff64e6)

scripts/libmakepkg/tidy/emptydirs.sh.in

@@ -33,6 +33,7 @@ tidy_remove+=('tidy_emptydirs')
 tidy_emptydirs() {
 	if check_option "emptydirs" "n"; then
 		msg2 "$(gettext "Removing empty directories...")"
-		find . -depth -type d -exec rmdir '{}' + 2>/dev/null
+		# we are unable to use '-empty' as it is non-POSIX and not support by all find variants
+		find . -depth -type d -exec rmdir '{}' \; 2>/dev/null
 	fi
 }