debug/ltrace: fix building for mips

ltrace 0.5.3 currently fails to build for target mips because MY_TARGET
(introduced by patches/ltrace/0.5.3/150-allow-configurable-arch.patch)
is set to 'mips' via CT_ARCH, while the mips specific stuff in ltrace
(0.5.3) is stored under sysdeps/linux-gnu/mipsel:

result: *** No rule to make target `mips/arch.h', needed by `sysdep.h'.
Stop.

The following patch fixes this issue

Signed-off-by: "Horst Kronstorfer" <horst.kronstorfer@aon.at>
[yann.morin.1998@anciens.enib.fr: reformat commit log]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
(transplanted from 2115901c7f07181d92ddbd7dd7ebeaa72e4fb176)

#!@@CT_bash@@

# What we need:

#  - the .config file

# Parse the tools' paths configuration

. "${CT_LIB_DIR}/paths.mk"

# We'll need the stdout later, save it

exec 7>&1

# Parse the common functions

. "${CT_LIB_DIR}/scripts/functions"

# Don't care about any log file

exec >/dev/null

rm -f "${tmp_log_file}"

# Parse the configuration file

. .config

# Parse architecture and kernel specific functions

. "${CT_LIB_DIR}/scripts/build/arch/${CT_ARCH}.sh"

. "${CT_LIB_DIR}/scripts/build/kernel/${CT_KERNEL}.sh"

# Build CT_TARGET

CT_DoBuildTargetTuple

# All this for this single echo... :-( Sigh, I'll have to re-arrange things...

echo "${CT_TARGET}" >&7