powerpc/ftrace: Remove ftrace_plt_tramps[]

ftrace_plt_tramps table is never filled so it is useless.

Remove it.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/daeeb618a6619e3a7e3f82f1bd83ca7c25af6330.1652074503.git.christophe.leroy@csgroup.eu

arch/powerpc/kernel/trace/ftrace.c

@@ -250,7 +250,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 	int i;
 	ppc_inst_t op;
 	unsigned long ptr;
-	static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS];
 
 	/* Is this a known long jump tramp? */
 	for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
@@ -259,13 +258,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 		else if (ftrace_tramps[i] == tramp)
 			return 0;
 
-	/* Is this a known plt tramp? */
-	for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
-		if (!ftrace_plt_tramps[i])
-			break;
-		else if (ftrace_plt_tramps[i] == tramp)
-			return -1;
-
 	/* New trampoline -- read where this goes */
 	if (copy_inst_from_kernel_nofault(&op, (void *)tramp)) {
 		pr_debug("Fetching opcode failed.\n");