ggml : fix A indexing in simd_gemm scalar tail-column path (#25390)

`simd_gemm()` has an incorrect A-matrix index in the scalar tail-column path for full row blocks.

diff --git a/ggml/src/ggml-cpu/simd-gemm.h b/ggml/src/ggml-cpu/simd-gemm.h
index 4119d04f895a8d91ad0ba60b798adb9fd61568d0..2ebd10051ed82ac3d509cad1552fb43661674e21 100644 (file)
--- a/ggml/src/ggml-cpu/simd-gemm.h
+++ b/ggml/src/ggml-cpu/simd-gemm.h
@@ -78,7 +78,7 @@ static void simd_gemm(
             for (int64_t i = 0; i < GEMM_RM; i++) {
                 float a = C[i * N + jj];
                 for (int64_t kk = 0; kk < K; kk++) {
-                    a += A[i + kk] * B[kk * N + jj];
+                    a += A[i * K + kk] * B[kk * N + jj];
                 }
                 C[i * N + jj] = a;
             }