OPP: debugfs: Fix warning around icc_get_name()

OPP: debugfs: Fix warning around icc_get_name()

If the kernel isn't built with interconnect support, icc_get_name()
returns NULL and we get following warning:

drivers/opp/debugfs.c: In function 'bw_name_read':
drivers/opp/debugfs.c:43:42: error: '%.62s' directive argument is null [-Werror=format-overflow=]
         i = scnprintf(buf, sizeof(buf), "%.62s\n", icc_get_name(path));

Fix it.

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Fixes: 0430b1d5704b0 ("opp: Expose bandwidth information via debugfs")
Signed-off-by: Viresh Kumar <[email protected]>
Reviewed-by: Dhruva Gole <[email protected]>