[PATCH 3/7] gdb: fix shellcheck warnings SC2006 (use $() instead of ``) in gdbarch.sh

[Simon Marchi <simon.marchi@efficios.com>]

Fix all instances of:

    In gdbarch.sh line 2195:
            printf "            `echo "$function" | sed -e 's/./ /g'`  %s %s)\n" "$returntype" "$function"
                                ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

    Did you mean:
            printf "            $(echo "$function" | sed -e 's/./ /g')  %s %s)\n" "$returntype" "$function"

See here [1] for the rationale.

[1] https://github.com/koalaman/shellcheck/wiki/SC2006

gdb/ChangeLog:

	* gdbarch.sh: Use $(...) instead of `...`.
---
 gdb/gdbarch.sh | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index a934a7aa6bc1..0e89bd1900b3 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -67,7 +67,7 @@ ${line}"
 	    # The semantics of IFS varies between different SH's.  Some
 	    # treat ``;;' as three fields while some treat it as just two.
 	    # Work around this by eliminating ``;;'' ....
-	    line="`echo "${line}" | sed -e 's/;;/; ;/g' -e 's/;;/; ;/g'`"
+	    line="$(echo "${line}" | sed -e 's/;;/; ;/g' -e 's/;;/; ;/g')"
 
 	    OFS="${IFS}" ; IFS="[;]"
 	    eval read "${read}" <<EOF
@@ -2162,7 +2162,7 @@ do
 	printf "\n"
 	printf "void\n"
 	printf "set_gdbarch_%s (struct gdbarch *gdbarch,\n" "$function"
-        printf "            `echo "$function" | sed -e 's/./ /g'`  gdbarch_%s_ftype %s)\n" "$function" "$function"
+	printf "            %s  gdbarch_%s_ftype %s)\n" "$(echo "$function" | sed -e 's/./ /g')" "$function" "$function"
 	printf "{\n"
 	printf "  gdbarch->%s = %s;\n" "$function" "$function"
 	printf "}\n"
@@ -2192,7 +2192,7 @@ do
 	printf "\n"
 	printf "void\n"
 	printf "set_gdbarch_%s (struct gdbarch *gdbarch,\n" "$function"
-        printf "            `echo "$function" | sed -e 's/./ /g'`  %s %s)\n" "$returntype" "$function"
+	printf "            %s  %s %s)\n" "$(echo "$function" | sed -e 's/./ /g')" "$returntype" "$function"
 	printf "{\n"
 	printf "  gdbarch->%s = %s;\n" "$function" "$function"
 	printf "}\n"
-- 
2.26.2