regexp: remove redundant break

Breaks are implicit, and since there is no outer loop this one could not
mean a loop break that was missing a label.

Change-Id: Ie91018db1825aa8285c1aa55c9d28fc7ec7148af
Reviewed-on: https://go-review.googlesource.com/39691
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/regexp/onepass.go

@@ -364,7 +364,6 @@ func makeOnePass(p *onePassProg) *onePassProg {
 			}
 		case syntax.InstMatch, syntax.InstFail:
 			m[pc] = inst.Op == syntax.InstMatch
-			break
 		case syntax.InstRune:
 			m[pc] = false
 			if len(inst.Next) > 0 {