arm: initialize the ARM VFP header in the routine restore_fpu()

The ARM VFP header is a part of the VFP frame that makes
it unreasonable to have frame initialization split into
two routines. This patch moerges the ARM version of
the routine sigreturn_prep_fpu_frame() into restore_fpu()
and reduces the former into a stub.
Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

arch/arm/crtools.c

@@ -195,7 +195,8 @@ int restore_fpu(struct rt_sigframe *sigframe, CoreEntry *core)
 
 	memcpy(&aux->vfp.ufp.fpregs, CORE_THREAD_ARCH_INFO(core)->fpstate->vfp_regs, sizeof(aux->vfp.ufp.fpregs));
 	aux->vfp.ufp.fpscr = CORE_THREAD_ARCH_INFO(core)->fpstate->fpscr;
-
+	aux->vfp.magic = VFP_MAGIC;
+	aux->vfp.size = VFP_STORAGE_SIZE;
 	return 0;
 }
 
@@ -245,13 +246,3 @@ int restore_gpregs(struct rt_sigframe *f, UserArmRegsEntry *r)
 
 	return 0;
 }
-
-int sigreturn_prep_fpu_frame(struct rt_sigframe *sigframe, fpu_state_t *fpu_state)
-{
-	struct aux_sigframe *aux = (struct aux_sigframe *)&sigframe->sig.uc.uc_regspace;
-
-	aux->vfp.magic = VFP_MAGIC;
-	aux->vfp.size = VFP_STORAGE_SIZE;
-
-	return 0;
-}

arch/arm/include/asm/restorer.h

@@ -134,7 +134,7 @@ struct rt_sigframe {
 int restore_gpregs(struct rt_sigframe *f, UserArmRegsEntry *r);
 int restore_nonsigframe_gpregs(UserArmRegsEntry *r);
 
-int sigreturn_prep_fpu_frame(struct rt_sigframe *sigframe, fpu_state_t *fpu_state);
+static inline int sigreturn_prep_fpu_frame(struct rt_sigframe *sigframe, fpu_state_t *fpu_state) { return 0; }
 
 static inline void restore_tls(u32 tls) {
 	asm (