mem: Remove mut in MemoryRegion::from_bytes

This change is suggested by clippy.

Signed-off-by: Akira Moroo <retrage01@gmail.com>

Author: retrage

src/boot.rs

@@ -191,8 +191,8 @@ pub struct Header {
 impl Header {
     // Read a kernel header from the first two sectors of a file
     pub fn from_file(f: &mut dyn Read) -> Result<Self, Error> {
-        let mut data: [u8; 1024] = [0; 1024];
-        let mut region = MemoryRegion::from_bytes(&mut data);
+        let data: [u8; 1024] = [0; 1024];
+        let mut region = MemoryRegion::from_bytes(&data);
 
         f.seek(0)?;
         f.load_file(&mut region)?;

src/mem.rs

@@ -16,7 +16,7 @@ impl MemoryRegion {
     }
 
     /// Take a slice and turn it into a region of memory
-    pub fn from_bytes(data: &mut [u8]) -> MemoryRegion {
+    pub fn from_bytes(data: &[u8]) -> MemoryRegion {
         MemoryRegion {
             base: data.as_ptr() as u64,
             length: data.len() as u64,

src/pe.rs

@@ -78,7 +78,7 @@ impl<'a> Loader<'a> {
             return Err(Error::FileError);
         }
 
-        let dos_region = MemoryRegion::from_bytes(&mut data);
+        let dos_region = MemoryRegion::from_bytes(&data);
 
         // 'MZ' magic
         if dos_region.read_u16(0) != 0x5a4d {
@@ -92,7 +92,7 @@ impl<'a> Loader<'a> {
             return Err(Error::InvalidExecutable);
         }
 
-        let pe_region = MemoryRegion::from_bytes(&mut data[pe_header_offset as usize..]);
+        let pe_region = MemoryRegion::from_bytes(&data[pe_header_offset as usize..]);
 
         // The Microsoft specification uses offsets relative to the COFF area
         // which is 4 after the signature (so all offsets are +4 relative to the spec)
@@ -109,8 +109,7 @@ impl<'a> Loader<'a> {
         self.num_sections = pe_region.read_u16(6);
 
         let optional_header_size = pe_region.read_u16(20);
-        let optional_region =
-            MemoryRegion::from_bytes(&mut data[(24 + pe_header_offset) as usize..]);
+        let optional_region = MemoryRegion::from_bytes(&data[(24 + pe_header_offset) as usize..]);
 
         if optional_region.read_u16(0) != Self::OPTIONAL_HEADER_MAGIC {
             return Err(Error::InvalidExecutable);