MIPS: Fix delay slot emulation count in debugfs

Commit 432c6bac ("MIPS: Use per-mm page to execute branch delay slot
instructions") accidentally removed use of the MIPS_FPU_EMU_INC_STATS
macro from do_dsemulret, leading to the ds_emul file in debugfs always
returning zero even though we perform delay slot emulations.

Fix this by re-adding the use of the MIPS_FPU_EMU_INC_STATS macro.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: 432c6bac ("MIPS: Use per-mm page to execute branch delay slot instructions")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14301/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/math-emu/dsemul.c

@@ -298,5 +298,6 @@ bool do_dsemulret(struct pt_regs *xcp)
 	/* Set EPC to return to post-branch instruction */
 	xcp->cp0_epc = current->thread.bd_emu_cont_pc;
 	pr_debug("dsemulret to 0x%08lx\n", xcp->cp0_epc);
+	MIPS_FPU_EMU_INC_STATS(ds_emul);
 	return true;
 }