powerpc/test_emulate_step: Move extern declaration to sstep.h

fix checkpatch.pl warnings by moving extern declaration from source
file to headerfile.

Signed-off-by: Balamuruhan S <bala24@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200626095158.1031507-5-bala24@linux.ibm.com

arch/powerpc/include/asm/sstep.h

@@ -108,6 +108,8 @@ enum instruction_type {
 #define GET_PREFIX_RA(i)	(((i) >> 16) & 0x1f)
 #define GET_PREFIX_R(i)		((i) & (1ul << 20))
 
+extern s32 patch__exec_instr;
+
 struct instruction_op {
 	int type;
 	int reg;

arch/powerpc/lib/test_emulate_step.c

@@ -1150,7 +1150,6 @@ static int __init emulate_compute_instr(struct pt_regs *regs,
 					bool negative)
 {
 	int analysed;
-	extern s32 patch__exec_instr;
 	struct instruction_op op;
 
 	if (!regs || !ppc_inst_val(instr))
@@ -1176,7 +1175,6 @@ static int __init execute_compute_instr(struct pt_regs *regs,
 					struct ppc_inst instr)
 {
 	extern int exec_instr(struct pt_regs *regs);
-	extern s32 patch__exec_instr;
 
 	if (!regs || !ppc_inst_val(instr))
 		return -EINVAL;