script/vendor/inject: remove erroneous check

the boarddir variable is only set *after* detect_board
is run, and is in fact checked after that. this check,
removed by this patch, is too early and causes lbmk
to exit with error states. this patch fixes the error.

the error was that lbmk was then searching for a file
that is at an empty path.

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

script/vendor/inject

@@ -82,7 +82,6 @@ detect_board()
 	*)
 		err "detect_board $filename: could not detect board type"
 	esac	
-	[ -d "$boarddir" ] || err "detect_board: dir \"$boarddir\" missing"
 	printf "%s\n" "${board}"
 }