frudevice: align readFromEeprom with readBlockData

To step closer to refactoring the FRU reading code, align the signatures
of the block mead methods.

Tested: This patch was not tested.
Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I431037604a92d748a64d1090d349616808f796ea
diff --git a/src/FruDevice.cpp b/src/FruDevice.cpp
index 87b7d40..db04ecc 100644
--- a/src/FruDevice.cpp
+++ b/src/FruDevice.cpp
@@ -101,8 +101,8 @@
     }
 }
 
-static ssize_t readFromEeprom(int fd, uint16_t offset, uint8_t len,
-                              uint8_t* buf)
+static int readFromEeprom(int flag __attribute__((unused)), int fd,
+                          uint16_t offset, uint8_t len, uint8_t* buf)
 {
     auto result = lseek(fd, offset, SEEK_SET);
     if (result < 0)
@@ -111,7 +111,7 @@
         return -1;
     }
 
-    return read(fd, buf, len);
+    return static_cast<int>(read(fd, buf, len));
 }
 
 static bool isMuxBus(size_t bus)
@@ -250,7 +250,7 @@
         return device;
     }
 
-    ssize_t readBytes = readFromEeprom(file, 0, 0x8, blockData.data());
+    int readBytes = readFromEeprom(0, file, 0, 0x8, blockData.data());
     if (readBytes < 0)
     {
         std::cerr << "failed to read eeprom at " << bus << " address "
@@ -286,7 +286,7 @@
 
         areaOffset *= 8;
 
-        if (readFromEeprom(file, static_cast<uint16_t>(areaOffset), 0x2,
+        if (readFromEeprom(0, file, static_cast<uint16_t>(areaOffset), 0x2,
                            blockData.data()) < 0)
         {
             std::cerr << "failed to read bus " << bus << " address " << address
@@ -311,7 +311,7 @@
     {
         int requestLength = std::min(I2C_SMBUS_BLOCK_MAX, fruLength);
 
-        if (readFromEeprom(file, static_cast<uint16_t>(readOffset),
+        if (readFromEeprom(0, file, static_cast<uint16_t>(readOffset),
                            static_cast<uint8_t>(requestLength),
                            blockData.data()) < 0)
         {