Fix a few minor issues (#473)

Changes:
- Fixed two xtrace test failures introduced in commit cfc8744c.
- The definition of _use_ntfork_tcpgrp in xec.c is now dependent on
  SHOPT_SPAWN being defined (re: 8e9ed5be).
- Removed many unnecessary newlines and fixed various typos.

src/cmd/ksh93/sh/fault.c

@@ -348,7 +348,6 @@ void	sh_sigreset(register int mode)
 				free(trap);
 			sh.st.trap[sig] = 0;
 		}
-		
 	}
 	if(sh.st.trapcom[0] && sh.st.trapcom[0] != Empty)
 		free(sh.st.trapcom[0]);