fix asserts in new premul inline function

git-svn-id: http://skia.googlecode.com/svn/trunk@1773 2bbb7eff-a529-9590-31e7-b0007b416f81

include/core/SkColorPriv.h

@@ -219,9 +219,9 @@ static inline SkPMColor SkPackARGB32NoCheck(U8CPU a, U8CPU r, U8CPU g, U8CPU b)
 static inline
 SkPMColor SkPremultiplyARGBInline(U8CPU a, U8CPU r, U8CPU g, U8CPU b) {
     SkA32Assert(a);
-    SkASSERT(r <= a);
+    SkA32Assert(r);
-    SkASSERT(g <= a);
+    SkA32Assert(g);
-    SkASSERT(b <= a);
+    SkA32Assert(b);
 
     if (a != 255) {
         r = SkMulDiv255Round(r, a);