Fix some typos detected by Debian's lintian QA tool

I assume the demoninator is a typo, rather than an indication that
someone has been playing too much Doom :-)

Signed-off-by: Simon McVittie <smcv@collabora.com>

include/SDL3/SDL_gpu.h

@@ -1158,7 +1158,7 @@ typedef enum SDL_GPUCompareOp
     SDL_GPU_COMPAREOP_LESS_OR_EQUAL,     /**< The comparison evaluates reference <= test. */
     SDL_GPU_COMPAREOP_GREATER,           /**< The comparison evaluates reference > test. */
     SDL_GPU_COMPAREOP_NOT_EQUAL,         /**< The comparison evaluates reference != test. */
-    SDL_GPU_COMPAREOP_GREATER_OR_EQUAL,  /**< The comparison evalutes reference >= test. */
+    SDL_GPU_COMPAREOP_GREATER_OR_EQUAL,  /**< The comparison evaluates reference >= test. */
     SDL_GPU_COMPAREOP_ALWAYS             /**< The comparison always evaluates true. */
 } SDL_GPUCompareOp;
 
@@ -2878,7 +2878,7 @@ extern SDL_DECLSPEC void SDLCALL SDL_InsertGPUDebugLabel(
     const char *text);
 
 /**
- * Begins a debug group with an arbitary name.
+ * Begins a debug group with an arbitrary name.
  *
  * Used for denoting groups of calls when viewing the command buffer
  * callstream in a graphics debugging tool.