[OS-BUILD PATCH] redhat/Makefile: Fix RHJOBS grep warning

[Prarit Bhargava (via Email Bridge)]

From: Prarit Bhargava

redhat/Makefile: Fix RHJOBS grep warning

Calculating RHJOBS results in the warning

grep: warning: stray \ before white space

Resolve this by using [ ] to detect a space in the regex.

Before fix:

Search for "before white space" in https://s3.amazonaws.com/arr-cki-prod-trusted-artifacts/trusted-artifacts/68...

After fix:

No "before white space" errors seen in https://s3.amazonaws.com/arr-cki-prod-trusted-artifacts/trusted-artifacts/69...

Also, confirming that RHJOBS works correctly after the fix,

[prarit@prarit kernel-ark]$ make -j13 dist-dump-variables | grep RHJOBS=
RHJOBS=13
[prarit@prarit kernel-ark]$

Signed-off-by: Prarit Bhargava

diff --git a/redhat/Makefile b/redhat/Makefile
index blahblah..blahblah 100644
--- a/redhat/Makefile
+++ b/redhat/Makefile
@@ -80,7 +80,7 @@ ifndef DISTRO
 endif

ifndef RHJOBS
-  RHJOBS=$(shell j=$$(echo $(MAKEFLAGS) | grep -Eo "\ -j[0-9]*" | xargs ); \
+  RHJOBS=$(shell j=$$(echo $(MAKEFLAGS) | grep -Eo "[ ]-j[0-9]*" | xargs ); \
      if [ -z "$${j}" ]; then \
      	echo "1"; \
      else \

--
https://gitlab.com/cki-project/kernel-ark/-/merge_requests/2148

[Herton R. Krzesinski (via Email Bridge)]

From: Herton R. Krzesinski on gitlab.com
https://gitlab.com/cki-project/kernel-ark/-/merge_requests/2148#note_1174863...

So there is a problem in this expression I think, but it was already an
existing problem before this change.

If you have eg.: ```MAKEFLAGS="-j45"```, be at the beginning or -j being the
only option in the MAKEFLAGS, the expression will not match.

I think the expression need to be changed to: ```grep -Eo "(^|[ ])-j[0-9]*"```
So it matches either at the beginning, or as an option in the middle of other
options with the space.