patch 8.1.0464: MS-Windows: job_info() has cmd without backslashes

Problem:    MS-Windows: job_info() has cmd without backslashes. (Daniel
            Hahler)
Solution:   Use rem_backslash(). (closes #3517, closes #3404)
diff --git a/src/misc2.c b/src/misc2.c
index 754fcdc..ad96bea 100644
--- a/src/misc2.c
+++ b/src/misc2.c
@@ -6458,14 +6458,14 @@
 	    while (*p != NUL && (inquote || (*p != ' ' && *p != TAB)))
 	    {
 		if (p[0] == '"')
-		    /* quotes surrounding an argument and are dropped */
+		    // quotes surrounding an argument and are dropped
 		    inquote = !inquote;
 		else
 		{
-		    if (p[0] == '\\' && p[1] != NUL)
+		    if (rem_backslash(p))
 		    {
-			/* First pass: skip over "\ " and "\"".
-			 * Second pass: Remove the backslash. */
+			// First pass: skip over "\ " and "\"".
+			// Second pass: Remove the backslash.
 			++p;
 		    }
 		    if (i == 1)