python: do not replace ccache in the middle of a path
Python recipe did a sed s/ccache/$(CCACHE) on the Makefile, which
replaces all "ccache" including ones that consist of a full path.
This leads to build error when building in a project path with
"ccache" in its name. Fix it by only replacing "ccache " with
"$(CCACHE) ".
(From OE-Core master rev:
1181112cf65bc0186807fc59399c5dddcb9f9449)
Signed-off-by: Lei Liu <lei.liu2@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
