Fix non-OpenMP build

rtengine/cfa_linedn_RT.cc

@@ -64,7 +64,9 @@ void RawImageSource::CLASS cfa_linedn(float noise, bool horizontal, bool vertica
     float noisevarm4 = 4.0f * noisevar;
     volatile double progress = 0.0;
     float* RawDataTmp = (float*)malloc( width * height * sizeof(float));
+#ifdef _OPENMP
     #pragma omp parallel
+#endif
     {
 
         // allocate memory and assure the arrays don't have same 64 byte boundary to avoid L1 conflict misses
@@ -76,7 +78,9 @@ void RawImageSource::CLASS cfa_linedn(float noise, bool horizontal, bool vertica
         float linehvar[4], linevvar[4], noisefactor[4][8][2], coeffsq;
         float dctblock[4][8][8];
 
+#ifdef _OPENMP
         #pragma omp for
+#endif
 
         for(int i = 0; i < height; i++)
             for(int j = 0; j < width; j++) {
@@ -84,7 +88,9 @@ void RawImageSource::CLASS cfa_linedn(float noise, bool horizontal, bool vertica
             }
 
         // Main algorithm: Tile loop
+#ifdef _OPENMP
         #pragma omp for schedule(dynamic) collapse(2)
+#endif
 
         for (int top = 0; top < height - 16; top += TS - 32)
             for (int left = 0; left < width - 16; left += TS - 32) {
@@ -251,7 +257,9 @@ void RawImageSource::CLASS cfa_linedn(float noise, bool horizontal, bool vertica
         free(cfain);
 
 // copy temporary buffer back to image matrix
+#ifdef _OPENMP
         #pragma omp for schedule(dynamic,16)
+#endif
 
         for(int i = 0; i < height; i++) {
             float f = rowblender(i);