x86/fpu: Rename fpu_reset_fpregs() to fpu_reset_fpstate_regs()

x86/fpu: Rename fpu_reset_fpregs() to fpu_reset_fpstate_regs()

The original function name came from an overly compressed form of
'fpstate_regs' by commit:

    e61d6310a0f8 ("x86/fpu: Reset permission and fpstate on exec()")

However, the term 'fpregs' typically refers to physical FPU registers. In
contrast, this function copies the init values to fpu->fpstate->regs, not
hardware registers.

Rename the function to better reflect what it actually does.

No functional change.

Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20250416021720.12305-11-chang.seok.bae@intel.com