ipmiutil: fix stack protector test

Add a patch that corrects detection of toolchain stack protector support when
libssp is missing.

Fixes:
http://autobuild.buildroot.net/results/497/497d2739c27ce0dcf91bdf2f87c02fc169ba9071/
http://autobuild.buildroot.net/results/f71/f71a4bbca2505fcacb396bcc643c7152d87b5283/
http://autobuild.buildroot.net/results/85d/85da63d49086f8cc62e2c67632dfdc39d7702169/



and more.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>