x86,kgdb: remove unnecessary call to kgdb_correct_hw_break()

The kernel debug_core invokes hw breakpoint install and removal via
call backs.  The architecture specific kgdb stubs only need to
implement the call backs and not actually call the functions.

Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
CC: x86@kernel.org
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: H. Peter Anvin <hpa@zytor.com>