x86/vdso: Fix building on big endian host

We need to call GET_LE to read hdr->e_type.

Fixes: 57f90c3 ("x86/vdso: Error out if the vDSO isn't a valid DSO")
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: linux-next@vger.kernel.org
Link: http://lkml.kernel.org/r/20160929193442.GA16617@gate.crashing.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Author: segher

arch/x86/entry/vdso/vdso2c.h

@@ -22,7 +22,7 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 
 	ELF(Phdr) *pt = (ELF(Phdr) *)(raw_addr + GET_LE(&hdr->e_phoff));
 
-	if (hdr->e_type != ET_DYN)
+	if (GET_LE(&hdr->e_type) != ET_DYN)
 		fail("input is not a shared object\n");
 
 	/* Walk the segment table. */