x86/insn: Fix awk regexp warnings

gawk 5.0.1 generates the following regexp warnings:

  GEN      /home/sasha/torvalds/tools/objtool/arch/x86/lib/inat-tables.c
  awk: ../arch/x86/tools/gen-insn-attr-x86.awk:260: warning: regexp escape sequence `\:' is not a known regexp operator
  awk: ../arch/x86/tools/gen-insn-attr-x86.awk:350: (FILENAME=../arch/x86/lib/x86-opcode-map.txt FNR=41) warning: regexp escape sequence `\&' is  not a known regexp operator

Ealier versions of gawk are not known to generate these warnings. The
gawk manual referenced below does not list characters ':' and '&' as
needing escaping, so 'unescape' them. See

  https://www.gnu.org/software/gawk/manual/html_node/Escape-Sequences.html

for more info.

Running diff on the output generated by the script before and after
applying the patch reported no differences.

 [ bp: Massage commit message. ]

[ Caught the respective tools header discrepancy. ]
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Alexander Kapshuk <alexander.kapshuk@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190924044659.3785-1-alexander.kapshuk@gmail.com

arch/x86/tools/gen-insn-attr-x86.awk

@@ -69,7 +69,7 @@ BEGIN {
 
 	lprefix1_expr = "\\((66|!F3)\\)"
 	lprefix2_expr = "\\(F3\\)"
-	lprefix3_expr = "\\((F2|!F3|66\\&F2)\\)"
+	lprefix3_expr = "\\((F2|!F3|66&F2)\\)"
 	lprefix_expr = "\\((66|F2|F3)\\)"
 	max_lprefix = 4
 
@@ -257,7 +257,7 @@ function convert_operands(count,opnd,       i,j,imm,mod)
 	return add_flags(imm, mod)
 }
 
-/^[0-9a-f]+\:/ {
+/^[0-9a-f]+:/ {
 	if (NR == 1)
 		next
 	# get index

tools/arch/x86/tools/gen-insn-attr-x86.awk

@@ -69,7 +69,7 @@ BEGIN {
 
 	lprefix1_expr = "\\((66|!F3)\\)"
 	lprefix2_expr = "\\(F3\\)"
-	lprefix3_expr = "\\((F2|!F3|66\\&F2)\\)"
+	lprefix3_expr = "\\((F2|!F3|66&F2)\\)"
 	lprefix_expr = "\\((66|F2|F3)\\)"
 	max_lprefix = 4
 
@@ -257,7 +257,7 @@ function convert_operands(count,opnd,       i,j,imm,mod)
 	return add_flags(imm, mod)
 }
 
-/^[0-9a-f]+\:/ {
+/^[0-9a-f]+:/ {
 	if (NR == 1)
 		next
 	# get index