x86/crc: add ANNOTATE_NOENDBR to suppress objtool warnings

The assembly functions generated by crc-pclmul-template.S are called
only via static_call, so they do not need to begin with an endbr
instruction.  But objtool still warns about a missing endbr by default.
Add ANNOTATE_NOENDBR to suppress these warnings:

    vmlinux.o: warning: objtool: crc32_x86_init+0x1c0: relocation to !ENDBR: crc32_lsb_vpclmul_avx10_256+0x0
    vmlinux.o: warning: objtool: crc64_x86_init+0x183: relocation to !ENDBR: crc64_msb_vpclmul_avx10_256+0x0
    vmlinux.o: warning: objtool: crc_t10dif_x86_init+0x183: relocation to !ENDBR: crc16_msb_vpclmul_avx10_256+0x0
    vmlinux.o: warning: objtool: __SCK__crc32_lsb_pclmul+0x0: data relocation to !ENDBR: crc32_lsb_pclmul_sse+0x0
    vmlinux.o: warning: objtool: __SCK__crc64_lsb_pclmul+0x0: data relocation to !ENDBR: crc64_lsb_pclmul_sse+0x0
    vmlinux.o: warning: objtool: __SCK__crc64_msb_pclmul+0x0: data relocation to !ENDBR: crc64_msb_pclmul_sse+0x0
    vmlinux.o: warning: objtool: __SCK__crc16_msb_pclmul+0x0: data relocation to !ENDBR: crc16_msb_pclmul_sse+0x0

Fixes: 8d2d3e7 ("x86/crc: add "template" for [V]PCLMULQDQ based CRC functions")
Reported-by: Stephen Rothwell <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]/
Suggested-by: Peter Zijlstra <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Eric Biggers <[email protected]>

Author: ebiggers

arch/x86/lib/crc-pclmul-template.S

@@ -7,6 +7,7 @@
 // Author: Eric Biggers <[email protected]>
 
 #include <linux/linkage.h>
+#include <linux/objtool.h>
 
 // Offsets within the generated constants table
 .set OFFSETOF_BSWAP_MASK,			-5*16	// msb-first CRCs only
@@ -272,6 +273,10 @@
 	.set	CONSTS_YMM,	%ymm7
 	.set	CONSTS_XMM,	%xmm7
 
+	// Use ANNOTATE_NOENDBR to suppress an objtool warning, since the
+	// functions generated by this macro are called only by static_call.
+	ANNOTATE_NOENDBR
+
 #ifdef __i386__
 	push		CONSTS_PTR
 	mov		8(%esp), CONSTS_PTR