buildgcc: Remove quotes around a $CC call

If we use ccache we have to interpret spaces in $CC as separation
characters. The downside is that we can't support spaces in the
compiler's path. But, well...

Change-Id: I4e6e6324389354669a755f570083a40ff00b1bbf
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/18018
Reviewed-by: Martin Roth <martinroth@google.com>
Tested-by: build bot (Jenkins)
1 file changed