Cleanup: spelling

One of the corrections from last cleanup was wrong.

source/blender/blenlib/intern/math_vector.c

@@ -122,7 +122,7 @@ bool interp_v2_v2v2_slerp(float target[2], const float a[2], const float b[2], c
 void interp_v3_v3v3_slerp_safe(float target[3], const float a[3], const float b[3], const float t)
 {
   if (UNLIKELY(!interp_v3_v3v3_slerp(target, a, b, t))) {
-    /* axis are aligned so any otho vector is acceptable */
+    /* Axis are aligned so any orthogonal vector is acceptable. */
     float ab_ortho[3];
     ortho_v3_v3(ab_ortho, a);
     normalize_v3(ab_ortho);
@@ -143,7 +143,7 @@ void interp_v3_v3v3_slerp_safe(float target[3], const float a[3], const float b[
 void interp_v2_v2v2_slerp_safe(float target[2], const float a[2], const float b[2], const float t)
 {
   if (UNLIKELY(!interp_v2_v2v2_slerp(target, a, b, t))) {
-    /* axis are aligned so any otho vector is acceptable */
+    /* Axis are aligned so any orthogonal vector is acceptable. */
     float ab_ortho[2];
     ortho_v2_v2(ab_ortho, a);
     // normalize_v2(ab_ortho);

source/blender/bmesh/tools/bmesh_bevel.c

@@ -1739,7 +1739,8 @@ static void calculate_profile(BevelParams *bp, BoundVert *bndv, bool reversed, b
   }
   if (bp->vmesh_method == BEVEL_VMESH_CUTOFF && map_ok) {
     /* Calculate the "height" of the profile by putting the (0,0) and (1,1) corners of the
-     * un-transformed profile thought the 2D->3D map and calculating the distance between them. */
+     * un-transformed profile throughout the 2D->3D map and calculating the distance between them.
+     */
     zero_v3(p);
     mul_v3_m4v3(bottom_corner, map, p);
     p[0] = 1.0f;

source/blender/editors/mesh/editmesh_knife.c

@@ -1612,7 +1612,9 @@ static void knife_find_line_hits(KnifeTool_OpData *kcd)
   mul_m4_v3(kcd->ob->imat, v3);
   mul_m4_v3(kcd->ob->imat, v4);
 
-  /* numeric error, 'v1' -> 'v2', 'v2' -> 'v4' can end up being ~2000 units apart in otho mode
+  /* Numeric error, 'v1' -> 'v2', 'v2' -> 'v4'
+   * can end up being ~2000 units apart with an orthogonal perspective.
+   *
    * (from ED_view3d_win_to_segment_clipped() above)
    * this gives precision error; rather then solving properly
    * (which may involve using doubles everywhere!),

source/blender/makesdna/DNA_tracking_types.h

@@ -147,7 +147,7 @@ typedef struct MovieTrackingTrack {
 
   /* ** control how tracking happens */
   /**
-   * Number of frames to be tarcked during single tracking session
+   * Number of frames to be tracked during single tracking session
    * (if TRACKING_FRAMES_LIMIT is set).
    */
   short frames_limit;