Addressing all the FIXMEs in the code

Includes better error handling in fft/mdct init
diff --git a/libcelt/modes.c b/libcelt/modes.c
index 968bc2f..0ba8d16 100644
--- a/libcelt/modes.c
+++ b/libcelt/modes.c
@@ -381,19 +381,15 @@
 
    compute_pulse_cache(mode, mode->maxLM);
 
-   clt_mdct_init(&mode->mdct, 2*mode->shortMdctSize*mode->nbShortMdcts, mode->maxLM);
-   if ((mode->mdct.trig==NULL)
-#ifndef ENABLE_TI_DSPLIB55
-         || (mode->mdct.kfft==NULL)
-#endif
-   )
+   if (clt_mdct_init(&mode->mdct, 2*mode->shortMdctSize*mode->nbShortMdcts,
+           mode->maxLM) == 0)
       goto failure;
 
    if (error)
       *error = CELT_OK;
 
    return mode;
-failure: 
+failure:
    if (error)
       *error = CELT_ALLOC_FAIL;
    if (mode!=NULL)