linux: Fix function point cast on vDSO handling

There is no need to cast to avoid, both pointer already have the
expected type.

sysdeps/unix/sysv/linux/gettimeofday.c

@@ -41,7 +41,7 @@ __gettimeofday_syscall (struct timeval *restrict tv, void *restrict tz)
 libc_ifunc (__gettimeofday,
 	    GLRO(dl_vdso_gettimeofday) != NULL
 	    ? VDSO_IFUNC_RET (GLRO(dl_vdso_gettimeofday))
-	    : (void *) __gettimeofday_syscall)
+	    : __gettimeofday_syscall)
 
 # else
 int

sysdeps/unix/sysv/linux/powerpc/libc-vdso.h

@@ -47,7 +47,7 @@
   ({                                                     \
     static Elf64_FuncDesc vdso_opd = { .fd_toc = ~0x0 }; \
     vdso_opd.fd_func = (Elf64_Addr)value;                \
-    &vdso_opd;                                           \
+    (void *) &vdso_opd;                                  \
   })
 
 #else

sysdeps/unix/sysv/linux/time.c

@@ -36,7 +36,7 @@ time_syscall (time_t *t)
 # define INIT_ARCH()
 libc_ifunc (time,
 	    GLRO(dl_vdso_time) != NULL ? VDSO_IFUNC_RET (GLRO(dl_vdso_time))
-				       : (void *) time_syscall);
+				       : time_syscall);
 
 # else
 time_t