libmakepkg/integrity: fix regression that broke invalid file sigs

In 42e7020281 creating the gpg statusfile
for a source file was split into a separate function, which used the
return code to indicate unsigned files and proto-specific errors.
However, the fallback return code was set by the final gpg invocation,
which would be 1 if the signature was somehow broken (for example, the
key was not available in the gpg keyring). As a result makepkg thought
that file did not have a signature and skipped over it rather than
erroring out.

Fix this by explicitly setting the return code for all
verify_*_signature() functions.

Signed-off-by: Eli Schwartz <eschwartz@archlinux.org>
Signed-off-by: Allan McRae <allan@archlinux.org>

scripts/libmakepkg/integrity/verify_signature.sh.in

@@ -157,6 +157,7 @@ verify_file_signature() {
 	esac
 
 	$decompress < "$sourcefile" | gpg --quiet --batch --status-file "$statusfile" --verify "$file" - 2> /dev/null
+	return 0
 }
 
 verify_git_signature() {
@@ -193,6 +194,7 @@ verify_git_signature() {
 		errors=1
 		return 1
 	fi
+	return 0
 }
 
 parse_gpg_statusfile() {