[cipd] Fix ppc64le uname.

The uname was reported incorrectly, and should have read "ppc64le".
Update the script to reference this.

TBR=iannucci@chromium.org
BUG=chromium:773857
TEST=None

Change-Id: Ice5ffe1257333b2bc1bfef7da60dcea4ead4d4c8
Reviewed-on: https://chromium-review.googlesource.com/723162
Reviewed-by: Daniel Jacques <dnj@chromium.org>
Commit-Queue: Daniel Jacques <dnj@chromium.org>

cipd

@@ -38,7 +38,7 @@ case $UNAME in
   ppc64)  # best-effort support for 64-bit PowerPC: crbug.com/773857
     ARCH=ppc64
     ;;
-  ppcle64)  # best-effort support for 64-bit PowerPC/LE: crbug.com/773857
+  ppc64le)  # best-effort support for 64-bit PowerPC/LE: crbug.com/773857
     ARCH=ppc64le
     ;;
   aarch64)