riscv/mm/fault: Fix inline placement in vmalloc_fault() declaration

The "inline" keyword is in the wrong place in vmalloc_fault()
declaration:

>> arch/riscv/mm/fault.c:56:1: warning: 'inline' is not at beginning of declaration [-Wold-style-declaration]
      56 | static void inline vmalloc_fault(struct pt_regs *regs, int code, unsigned long addr)
         | ^~~~~~

Fix that up.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>