lexer: fix encoding 7 bit escape sequences

A misplaced paren caused escape sequences in the ranges \x00..\x7f,
\u0000..\u007f and \0..\177 to get improperly encoded into the
string buffer.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

lexer.c

@@ -55,7 +55,7 @@ utf8enc(char **out, int *rem, int code)
 		if (*rem < 1)
 			return false;
 
-		*(*out++) = code; (*rem)--;
+		*(*out)++ = code; (*rem)--;
 		return true;
 	}
 	else if (code > 0 && code <= 0x7FF)