Changed pointer variable names for clarity for SwiGLU (#46)

## Summary
Added _ptr to pointer variables for clarity in SwiGLU as we have done in
the other files.

## Testing Done
- [ x] run `make checkstyle` to ensure code style

src/liger_kernel/ops/swiglu.py

@@ -12,52 +12,52 @@ def silu(x):
 
 @triton.jit
 def _swiglu_forward_kernel(
-    a, b, c, stride, n_cols: tl.constexpr, BLOCK_SIZE: tl.constexpr
+    a_ptr, b_ptr, c_ptr, stride, n_cols: tl.constexpr, BLOCK_SIZE: tl.constexpr
 ):
     program_id = tl.program_id(0)
 
     # locate start index
-    a += program_id * stride
-    b += program_id * stride
-    c += program_id * stride
+    a_ptr += program_id * stride
+    b_ptr += program_id * stride
+    c_ptr += program_id * stride
 
     col_offsets = tl.arange(0, BLOCK_SIZE)
     mask = col_offsets < n_cols
 
     # sigmoid requires type float32
-    a_row = tl.load(a + col_offsets, mask=mask, other=0).to(tl.float32)
-    b_row = tl.load(b + col_offsets, mask=mask, other=0)
+    a_row = tl.load(a_ptr + col_offsets, mask=mask, other=0).to(tl.float32)
+    b_row = tl.load(b_ptr + col_offsets, mask=mask, other=0)
     c_row = silu(a_row) * b_row
-    tl.store(c + col_offsets, c_row, mask=mask)
+    tl.store(c_ptr + col_offsets, c_row, mask=mask)
 
 
 @triton.jit
 def _swiglu_backward_kernel(
-    dc, a, b, stride, n_cols: tl.constexpr, BLOCK_SIZE: tl.constexpr
+    dc_ptr, a_ptr, b_ptr, stride, n_cols: tl.constexpr, BLOCK_SIZE: tl.constexpr
 ):
     program_id = tl.program_id(0)
 
     # locate start index
-    dc += program_id * stride
-    a += program_id * stride
-    b += program_id * stride
+    dc_ptr += program_id * stride
+    a_ptr += program_id * stride
+    b_ptr += program_id * stride
 
     col_offsets = tl.arange(0, BLOCK_SIZE)
     mask = col_offsets < n_cols
 
-    dc_row = tl.load(dc + col_offsets, mask=mask, other=0)
+    dc_row = tl.load(dc_ptr + col_offsets, mask=mask, other=0)
     # sigmoid requires type float32
-    a_row = tl.load(a + col_offsets, mask=mask, other=0).to(tl.float32)
-    b_row = tl.load(b + col_offsets, mask=mask, other=0)
+    a_row = tl.load(a_ptr + col_offsets, mask=mask, other=0).to(tl.float32)
+    b_row = tl.load(b_ptr + col_offsets, mask=mask, other=0)
 
     # recomputation to save memory
     sig_a = tl.sigmoid(a_row)
     silu_a = a_row * sig_a
     db_row = dc_row * silu_a
     da_row = dc_row * (silu_a * (1 - sig_a) + sig_a) * b_row
 
-    tl.store(a + col_offsets, da_row, mask=mask)
-    tl.store(b + col_offsets, db_row, mask=mask)
+    tl.store(a_ptr + col_offsets, da_row, mask=mask)
+    tl.store(b_ptr + col_offsets, db_row, mask=mask)
 
 
 class LigerSiLUMulFunction(torch.autograd.Function):