BaseTools: Fixed the multiple pairs brackets issue in GenFv

BaseTools: Fixed the multiple pairs brackets issue in GenFv

If operation Werro is turned on when compiling BaseTools, the
multi-brackets warning will be reported. This issue is comes from on of
the LoongArch enabled patche. Removed extra pairs brackets to fix it.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4111

Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Yuwei Chen <yuwei.chen@intel.com>
Signed-off-by: Chao Li <lichao@loongson.cn>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>