rtlwifi: Remove unnecessary NULL check in rtl_regd_init

rtlwifi: Remove unnecessary NULL check in rtl_regd_init

When building with Clang + -Wtautological-pointer-compare:

drivers/net/wireless/realtek/rtlwifi/regd.c:389:33: warning: comparison
of address of 'rtlpriv->regd' equal to a null pointer is always false
[-Wtautological-pointer-compare]
        if (wiphy == NULL || &rtlpriv->regd == NULL)
                              ~~~~~~~~~^~~~    ~~~~
1 warning generated.

The address of an array member is never NULL unless it is the first
struct member so remove the unnecessary check. This was addressed in
the staging version of the driver in commit f986978b32b3 ("Staging:
rtlwifi: remove unnecessary NULL check").

While we are here, fix the following checkpatch warning:

CHECK: Comparison to NULL could be written "!wiphy"
35: FILE: drivers/net/wireless/realtek/rtlwifi/regd.c:389:
+       if (wiphy == NULL)

Fixes: 0c8173385e54 ("rtl8192ce: Add new driver")
Link:https://github.com/ClangBuiltLinux/linux/issues/750
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>