kbuild: fix up permissions on scripts/pahole-flags.sh

Commit b775fbf ("kbuild: Add skip_encoding_btf_enum64 option to
pahole") created the file scripts/pahole-flags.sh, but due to a mismatch
between patch and quilt and git, the execute permissions did not get set
properly.  Fix that up.

Reported-by: Florian Fainelli <f.fainelli@gmail.com>
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Fixes: b775fbf ("kbuild: Add skip_encoding_btf_enum64 option to pahole")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>