Fixed ImportError due to undefined symbolis in Shared object

C function definitions for multi-iterators moved to header file
need to be declared static to avoid being visible in the SO file.

Author: oleksandr-pavlyk

mkl_fft/src/multi_iter.h

@@ -72,7 +72,7 @@ void multi_iter_masked_free(multi_iter_masked_t*);
 int multi_iter_masked_next(multi_iter_masked_t*);
 */
 
-NPY_INLINE void
+static NPY_INLINE void
 multi_iter_new(multi_iter_t* mi, npy_intp shape[], int rank) {
     int i;
     char d = 0;
@@ -94,7 +94,7 @@ multi_iter_new(multi_iter_t* mi, npy_intp shape[], int rank) {
     return;
 }
 
-NPY_INLINE void
+static NPY_INLINE void
 multi_iter_masked_new(
     multi_iter_masked_t* mi, npy_intp shape[], int rank, int mask[], int mask_len) 
 {
@@ -124,7 +124,7 @@ multi_iter_masked_new(
 }
 
 
-NPY_INLINE void
+static NPY_INLINE void
 multi_iter_masked_free(multi_iter_masked_t *mi) {
     if (mi) {
 	if(MultiIter_Index(*mi))
@@ -140,7 +140,7 @@ multi_iter_masked_free(multi_iter_masked_t *mi) {
     return;
 }
 
-NPY_INLINE void
+static NPY_INLINE void
 multi_iter_free(multi_iter_t *mi) {
     if (mi) {
 	if(MultiIter_Index(*mi))
@@ -156,7 +156,7 @@ multi_iter_free(multi_iter_t *mi) {
 
 
 /* Modifies iterator in-place, returns 1 when iterator is empty, 0 otherwise */
-NPY_INLINE int
+static NPY_INLINE int
 multi_iter_next(multi_iter_t *mi) {
     int j, k;
 
@@ -178,7 +178,7 @@ multi_iter_next(multi_iter_t *mi) {
 }
 
 /* Modifies iterator in-place, returns 1 when iterator is empty, 0 otherwise */
-NPY_INLINE int
+static NPY_INLINE int
 multi_iter_masked_next(multi_iter_masked_t *mi) {
     int j, k;