fix(tf-coverity): fix regex used to extract the file names

Coverity script throw below error even though clk-stm32-core.c
got covered for analysis.

1 files were not analyzed:
 - drivers/st/clk/clk-stm32-core.c

To fix this issue updated regex used to extract the file names of
the analyzed files.

Change-Id: I3a1f1b336cd85585ece27e64ae44e1b82664afdf
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
1 file changed