staging: rtlwifi: Remove unnecessary parentheses

Clang warns when multiple pairs of parentheses are used for a single
conditional statement.

drivers/staging/rtlwifi/phydm/phydm_adc_sampling.c:558:33: warning:
equality comparison with extraneous parentheses [-Wparentheses-equality]
                } else if ((is_enable_la_mode == 1)) {
                            ~~~~~~~~~~~~~~~~~~^~~~
drivers/staging/rtlwifi/phydm/phydm_adc_sampling.c:558:33: note: remove
extraneous parentheses around the comparison to silence this warning
                } else if ((is_enable_la_mode == 1)) {
                           ~                  ^   ~
drivers/staging/rtlwifi/phydm/phydm_adc_sampling.c:558:33: note: use '='
to turn this equality comparison into an assignment
                } else if ((is_enable_la_mode == 1)) {
                                              ^~
                                              =
1 warning generated.

Link: https://github.com/ClangBuiltLinux/linux/issues/172


Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>