Allow matches of truncated version strings.

Long objdir paths make it easy to hit the version string length limit in
kernel dump headers. The build number and timestamp are unlikely to be
truncated and ought to be sufficient to protect against false positives.

Discussed with:	jhb
MFC after:	1 week

usr.sbin/crashinfo/crashinfo.sh

@@ -83,10 +83,12 @@ find_kernel()
 		}
 	}' $INFO)
 
-	# Look for a matching kernel version.
+	# Look for a matching kernel version, handling possible truncation
+	# of the version string recovered from the dump.
 	for k in `sysctl -n kern.bootfile` $(ls -t /boot/*/kernel); do
-		kvers=$(gdb_command $k 'printf "  Version String: %s", version' \
-		     2>/dev/null)
+		kvers=$(gdb_command $k 'printf "  Version String: %s", version' | \
+		    awk "{line=line\$0\"\n\"} END{print substr(line,1,${#ivers})}" \
+		    2>/dev/null)
 		if [ "$ivers" = "$kvers" ]; then
 			KERNEL=$k
 			break