Makefile: Subtle mix of double quotes.

In case of spaces and parentheses, the path must be protected for mktemp but also
for the --xml-file option. Hence the double double quotes.

The outer double quotes must not be escaped (otherwise double quotes are passed to valgrind
which is not good)

algo/tests/Makefile

@@ -11,7 +11,7 @@ SHOULD=$(wildcard *.should_get)
 SHOULD_LOG=$(SHOULD:.should_get=.tap)
 SHOULD_VDJ=$(wildcard should-vdj-tests/*.should-vdj.fa)
 REPORTS_PATH := $(patsubst %/Makefile,%,$(abspath $(lastword $(MAKEFILE_LIST))))/../../reports
-VALGRIND=valgrind -v --tool=memcheck --leak-check=full --show-reachable=yes --undef-value-errors=yes --track-origins=yes --xml=yes --xml-file=\"$$(mktemp "$(REPORTS_PATH)/valgrind.xml.XXXXXX")\"
+VALGRIND=valgrind -v --tool=memcheck --leak-check=full --show-reachable=yes --undef-value-errors=yes --track-origins=yes --xml=yes --xml-file="$$(mktemp "$(REPORTS_PATH)/valgrind.xml.XXXXXX")"
 
 .PHONY: all force clean forcedep