scripts/mksysmap: Fix badly escaped '$'

The backslash characters escaping '$' in the command to sed (intended to
prevent it from interpreting '$' as "end-of-line") are currently being
consumed by the Shell (where they mean that sh should not evaluate what
follows '$' as a variable name). This means that

    sed -e "/ \$/d"

executes the script

    / $/d

instead of the intended

    / \$/d

So escape twice in mksysmap any '$' that actually needs to reach sed
escaped so that the backslash survives the Shell.

Fixes: c480204 ("scripts/mksysmap: use sed with in-line comments")
Fixes: 320e7c9 ("scripts/kallsyms: move compiler-generated symbol patterns to mksysmap")
Signed-off-by: Pierre-Clément Tosi <ptosi@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Author: ptosi

scripts/mksysmap

@@ -32,7 +32,7 @@ ${NM} -n ${1} | sed >${2} -e "
 #  (do not forget a space before each pattern)
 
 # local symbols for ARM, MIPS, etc.
-/ \$/d
+/ \\$/d
 
 # local labels, .LBB, .Ltmpxxx, .L__unnamed_xx, .LASANPC, etc.
 / \.L/d
@@ -41,7 +41,7 @@ ${NM} -n ${1} | sed >${2} -e "
 / __efistub_/d
 
 # arm64 local symbols in non-VHE KVM namespace
-/ __kvm_nvhe_\$/d
+/ __kvm_nvhe_\\$/d
 / __kvm_nvhe_\.L/d
 
 # arm64 lld