subsys/settings: Correct size in strncpy to avoid unterminated strings

This fixes some Coverity warnings.

Coverity-CID: 198391
Coverity-CID: 198390
Coverity-CID: 198389
Fixes #15989
Fixes #15990
Fixes #15991

Signed-off-by: François Delawarde <fnde@oticon.com>
1 file changed