vendor.sh: optimise find_me()

i'm adding characters to 7ztest, which isn't being passed
on through because everything runs in subshells; the next
pass would default back to the original string, so a given
file may be checked multiple times.

fix this by mitigation; use the random string from mktemp
as a suffix instead.

in practice, this has not affected performance much, but it
will nevertheless avoid unnecessary work by xbmk.

Signed-off-by: Leah Rowe <leah@libreboot.org>

include/init.sh

@@ -181,7 +181,7 @@ pybin()
 	[ $venv -gt 0 ] && for pypath in "/usr/local/bin" "/usr/bin"; do
 		[ -e "$pypath/$1" ] && [ ! -d "$pypath/$1" ] && \
 		    [ -x "$pypath/$1" ] && printf "%s/%s\n" "$pypath" "$1" && \
-		    return 0
+		    return 0; :
 	done && return 1
 
 	# Defer to normal command -v if not a venv