did not compile

(btw irix test was ok: "test ! foo" means "not foo" but the comment
 was misleading)


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@2466 b3059339-0415-0410-9bf9-f77b7e298cf2

configure

@@ -892,7 +892,8 @@ cc_check $_extraincdir $_extralibdir -ltermcap && _termcap=yes
 
 _png=no
 if irix64 ; then
-  : Don't check for -lpng on irix	
+  # Don't check for -lpng on irix since irix has its own libpng
+  # incompatible with the GNU one
 else
   cc_check $_extraincdir $_extralibdir -lpng -lz -lm && _png=yes
 fi