Revert "cmake: fix webpmux lib name for cmake linking"
Revert "cmake: fix webpmux lib name for cmake linking"

This reverts commit 13b8281609113c4904877e637d4e8a775d8150bc.

This breaks target name compatibility with earlier releases.

Conflicts:
	CMakeLists.txt

Bug: webp:575
Change-Id: I3d4895b8a8d14b3f4595ec19646ec4a1001c7748

webmproject/libwebp,webmproject/libwebp,webmproject/libwebp,webmproject/libwebp,webmproject/libwebp