libregexp: fix copy-paste error

Change-Id: I042d63ea62e2abd599bf9767acb3374bb39ddc7d
Reviewed-on: https://plan9port-review.googlesource.com/1050
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Russ Cox <rsc@google.com>

src/libregexp/rregexec.c

diff --git a/src/libregexp/rregexec.c b/src/libregexp/rregexec.c
index 16d95e6..c3a1753 100644
--- a/src/libregexp/rregexec.c
+++ b/src/libregexp/rregexec.c
@@ -46,7 +46,7 @@
 			switch(j->starttype) {
 			case RUNE:
 				p = runestrchr(s, j->startchar);
-				if(p == 0 || p == j->reol)
+				if(p == 0 || s == j->reol)
 					return match;
 				s = p;
 				break;