networking: cc is not a register

networking: cc is not a register

gcc accepts

  __asm__ ( "" : : : "%cc");

but cc is not a real register and clang does not like it.

networking/tls_pstm_montgomery_reduce.c:385:4: error: unknown register name '%cc' in asm
|                         INNERMUL;
|                         ^

The % syntax nominally goes before a register, in this case cc,
like "memory" isn't a true register it's just a way of specifying that
the condition code registers for the target are clobbered

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>