scripts/functions: return a proper error code in CT_DoExecLog

Since we added the debug-shell feature, CT_DoExecLog no longer
returns the error code of the command, but always return 0.

This breaks the download mechanism, which relies on CT_DoExecLog
to fail _on_purpose_ to detect that the ressource was not found
at the specified URL.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

diff -dur ELFkickers.orig/sstrip/Makefile ELFkickers/sstrip/Makefile

--- ELFkickers.orig/sstrip/Makefile	2001-03-24 12:58:27.000000000 +0100

+++ ELFkickers/sstrip/Makefile	2007-05-31 21:17:18.000000000 +0200

@@ -1,7 +1,7 @@

 #  Makefile for sstrip

 sstrip: sstrip.c

-	gcc -ggdb -Wall -W -o sstrip sstrip.c

+	$(CC) -Wall -W -o sstrip sstrip.c

 clean:

 	rm -f sstrip