Ports/mrsh: Fix workdir, remove or upgrade patches

Also removes mrsh from the list of ports missing descriptions. I tried
to be descriptive about the patches, but as I picked this port up from
someone else, I'm not 100% sure how to best explain the patches.

Ports/mrsh/patches/0001-Add-SerenityOS-to-the-mrsh-build-system.patch

@@ -0,0 +1,46 @@
+From 4c9a77a1174cdc049d7dc418c43842920bd52f52 Mon Sep 17 00:00:00 2001
+From: EWouters <6179932+EWouters@users.noreply.github.com>
+Date: Tue, 12 Apr 2022 17:58:24 +0200
+Subject: [PATCH 1/4] Add SerenityOS to the mrsh build system
+
+---
+ configure            | 6 ++++--
+ libmrsh.serenity.sym | 7 +++++++
+ 2 files changed, 11 insertions(+), 2 deletions(-)
+ create mode 100644 libmrsh.serenity.sym
+
+diff --git a/configure b/configure
+index c0e918e..1bf7d26 100755
+--- a/configure
++++ b/configure
+@@ -230,9 +230,11 @@ else
+ fi
+ 
+ printf "Checking for exported symbol restrictions... "
+-if ! \
++if ! (\
+ 	test_ldflags -Wl,--version-script="libmrsh.gnu.sym" || \
+-	test_ldflags -Wl,-exported_symbols_list,"libmrsh.darwin.sym"
++	test_ldflags -Wl,-exported_symbols_list,"libmrsh.darwin.sym" || \
++	test_ldflags -Wl,--version-script="libmrsh.serenity.sym"
++)
+ then
+ 	echo no
+ 	echo "Unable to specify exported symbols (is $(uname) supported?)" >&2
+diff --git a/libmrsh.serenity.sym b/libmrsh.serenity.sym
+new file mode 100644
+index 0000000..33de4a1
+--- /dev/null
++++ b/libmrsh.serenity.sym
+@@ -0,0 +1,7 @@
++{
++	global:
++		mrsh_*;
++		main;
++	local:
++		*;
++};
+\ No newline at end of file
+-- 
+2.32.0 (Apple Git-132)
+