patch 8.1.1740: exepath() doesn't work for "bin/cat"

Problem:    Exepath() doesn't work for "bin/cat".
Solution:   Check for any path separator. (Daniel Hahler, closes #4724,
            closes #4710)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 3fbeec2..8b9fba0 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -3058,8 +3058,7 @@
     char_u *name = tv_get_string(&argvars[0]);
 
     /* Check in $PATH and also check directly if there is a directory name. */
-    rettv->vval.v_number = mch_can_exe(name, NULL, TRUE)
-		 || (gettail(name) != name && mch_can_exe(name, NULL, FALSE));
+    rettv->vval.v_number = mch_can_exe(name, NULL, TRUE);
 }
 
 static garray_T	redir_execute_ga;