make SpecialLineRec::addSegment assert more permissive to accomodate rounding error

src/utils/SkDashPath.cpp

Index: src/utils/SkDashPath.cpp
diff --git a/src/utils/SkDashPath.cpp b/src/utils/SkDashPath.cpp
index e06c2d2da355bbb80ee30a98448b697b08a18647..c0cdcc195d20f0e8eed338922b4f47bea7c21a4d 100644
--- a/src/utils/SkDashPath.cpp
+++ b/src/utils/SkDashPath.cpp
@@ -186,7 +186,7 @@ public:
     }
 
     void addSegment(SkScalar d0, SkScalar d1, SkPath* path) const {
-        SkASSERT(d0 < fPathLength);
+        SkASSERT(d0 <= fPathLength);
         // clamp the segment to our length
         if (d1 > fPathLength) {
             d1 = fPathLength;