Makefile: Hide coverage helper targets if COV is not set

We only check COV=1 in `make coverage` before. This will result in
deleting all files in the current working directory if we accidentally
tried `make coverage_init`.

Hide coverage_init and coverage_html if COV is not set.

TEST=make coverage_init and see the error message
TEST=make clean && COV=1 make coverage -j

Signed-off-by: Hsuan Ting Chen <>
Change-Id: I2d22b211b3d9e59d12faa0ab3d1c2ca8433598f7
Reviewed-by: Yu-Ping Wu <>
1 file changed