HSI: omap_ssi: Fix return value check in ssi_debug_add_ctrl()
HSI: omap_ssi: Fix return value check in ssi_debug_add_ctrl()

In case of error, the function debugfs_create_*() returns NULL
pointer not ERR_PTR() if debugfs is enabled. The IS_ERR() test
in the return value check should be replaced with NULL test.

Signed-off-by: Wei Yongjun <b8f9cab8be13de37b9588aedad10a20fc3a68783@trendmicro.com.cn>
Signed-off-by: Sebastian Reichel <1ea78bda3cb6d36efdb8fc89aad6555e21b4887e@kernel.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs