Fix Cycles CUDA build error with Visual Studio 2019 v16.9

Something in this update broke the floor() function in CUDA, instead use
floorf() like we do everywhere else in the kernel code. Thanks to Ray
Molenkamp for identifying the solution.

intern/cycles/kernel/kernels/cuda/kernel_cuda_image.h

@@ -68,8 +68,8 @@ ccl_device T kernel_tex_image_interp_bicubic(const TextureInfo &info, float x, f
   x = (x * info.width) - 0.5f;
   y = (y * info.height) - 0.5f;
 
-  float px = floor(x);
-  float py = floor(y);
+  float px = floorf(x);
+  float py = floorf(y);
   float fx = x - px;
   float fy = y - py;
 
@@ -95,9 +95,9 @@ ccl_device T kernel_tex_image_interp_tricubic(const TextureInfo &info, float x,
   y = (y * info.height) - 0.5f;
   z = (z * info.depth) - 0.5f;
 
-  float px = floor(x);
-  float py = floor(y);
-  float pz = floor(z);
+  float px = floorf(x);
+  float py = floorf(y);
+  float pz = floorf(z);
   float fx = x - px;
   float fy = y - py;
   float fz = z - pz;
@@ -127,9 +127,9 @@ ccl_device T kernel_tex_image_interp_tricubic(const TextureInfo &info, float x,
 template<typename T, typename S>
 ccl_device T kernel_tex_image_interp_tricubic_nanovdb(S &s, float x, float y, float z)
 {
-  float px = floor(x);
-  float py = floor(y);
-  float pz = floor(z);
+  float px = floorf(x);
+  float py = floorf(y);
+  float pz = floorf(z);
   float fx = x - px;
   float fy = y - py;
   float fz = z - pz;