makepkg: fix one more file-seccomp issue

When file is called via fakeroot, it doesn't matter whether you use -z
or not, it is still incompatible with seccomp. Fix by configuring it
with FILECMD when used in the fakeroot 'tidy' run.

Fixes FS#65100

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

scripts/libmakepkg/tidy/strip.sh.in

@@ -111,7 +111,7 @@ tidy_strip() {
 
 		local binary strip_flags
 		find . -type f -perm -u+w -print0 2>/dev/null | while IFS= read -rd '' binary ; do
-			case "$(file -bi "$binary")" in
+			case "$(@FILECMD@ -bi "$binary")" in
 				*application/x-sharedlib*)  # Libraries (.so)
 					strip_flags="$STRIP_SHARED";;
 				*application/x-archive*)    # Libraries (.a)