gitweb/Makefile: fix typo in gitweb.min.css rule

This typo has been in place since the rule was originally added by
0e6ce213 (Gitweb: add support for minifying gitweb.css).
Signed-off-by: NJay Soffian <jaysoffian@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

gitweb/Makefile

@@ -91,7 +91,7 @@ ifdef CSSMIN
 GITWEB_CSS = gitweb.min.css
 all:: gitweb.min.css
 gitweb.min.css: gitweb.css GITWEB-BUILD-OPTIONS
-	$(QUIET_GEN)$(CSSMIN) <$ >$@
+	$(QUIET_GEN)$(CSSMIN) <$< >$@
 endif
 
 GITWEB_REPLACE = \