Revert "LoongArch: BPF: Fix off-by-one error in build_prologue()"

This reverts commit e9ccb26 which is
commit 7e2586991e36663c9bc48c828b83eab180ad30a9 upstream.

It breaks the build.

Link: https://lore.kernel.org/r/[email protected]
Reported-by: Guenter Roeck <[email protected]>
Cc: Vincent Li <[email protected]>
Cc: Hengqi Chen <[email protected]>
Cc: Huacai Chen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: gregkh

arch/loongarch/net/bpf_jit.c

@@ -142,8 +142,6 @@ static void build_prologue(struct jit_ctx *ctx)
 	 */
 	if (seen_tail_call(ctx) && seen_call(ctx))
 		move_reg(ctx, TCC_SAVED, REG_TCC);
-	else
-		emit_insn(ctx, nop);
 
 	ctx->stack_size = stack_adjust;
 }

arch/loongarch/net/bpf_jit.h

@@ -25,11 +25,6 @@ struct jit_data {
 	struct jit_ctx ctx;
 };
 
-static inline void emit_nop(union loongarch_instruction *insn)
-{
-	insn->word = INSN_NOP;
-}
-
 #define emit_insn(ctx, func, ...)						\
 do {										\
 	if (ctx->image != NULL) {						\