drm: sti: hdmi: fix return value check in sti_hdmi_probe()
drm: sti: hdmi: fix return value check in sti_hdmi_probe()

In case of error, the function devm_ioremap_nocache() returns NULL
pointer not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.

Signed-off-by: Wei Yongjun <b8f9cab8be13de37b9588aedad10a20fc3a68783@trendmicro.com.cn>

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