Fix a typo in CpuId breaking gcc-6.5 builds

Summary:
gcc-6.5 on OS X <= 10.6 complains about the `\r` when this code path
is enabled. I don't think we officially support `__i386__`, but I want to
backport the patch from zstd. https://github.com/facebook/zstd/pull/1418

(Note: this ignores all push blocking failures!)

Reviewed By: yfeldblum, Orvid

Differential Revision: D13104652

fbshipit-source-id: 737a68253c7d90c3a1cc026069b048551cb5ced9

folly/CpuId.h

@@ -82,7 +82,7 @@ class CpuId {
       __asm__(
           "pushl %%ebx\n\t"
           "cpuid\n\t"
-          "movl %%ebx, %%eax\n\r"
+          "movl %%ebx, %%eax\n\t"
           "popl %%ebx"
           : "=a"(f7b_), "=c"(f7c_)
           : "a"(7), "c"(0)